Stope mining machinery having free swinging hammers

ABSTRACT

Mining machinery and more particularly stoping machinery utilizing rotors carrying free swinging hammers with the rotors mounted to be tilted relative to the stope footwall to facilitate the cutting of slots in the rock wider than the machine.

United States Patent Taylor [451 June 28, 1974 [5 STOPE MINING MACHINERY HAVING FREE SWINGING HAMMERS' [75] Inventor: Richard F. Taylor, Johannesburg,

South Africa [73] Assignee: Anglo Transvaal Consolidated Investment Company Limited,

Johannesburg, South Africa 22 Filedz Feb. 29, 1972 21 App1.No.:230,337

[30] Foreign Application Priority Data Mar. 3, 1971 South Africa 71/1362 [52] US. Cl. 299/1, 299/43- [51] Int. Cl. EZlc 29/14 [58] Field of Search 299/43-52,

[5 6] References Cited UNITED STATES PATENTS 2,680,606 6/1954 Bolton 299/43 3,647,263 3/1972 Lauber et al. 299/71 X FOREIGN PATENTS OR APPLlCATIONS 1,172,208 6/1964 Germany 299/51 Primary ExaminerErnest R. Purser Attorney, Agent, or Firm-Stevens, Davis, Miller &

Mosher ABSTRACT Mining machinery and'more particularly stoping machinery utilizing rotors carrying free swinging hammers with the rotors mounted to be tilted relative to the stope footwall to facilitate the cutting of slots in the rock wider than the machine.

19 Claims, 4 Drawing Figures I STOPE MINING MACHINERY HAVING FREE SWINGING HAMMERS This invention relates to mining machinery and more particularly to such machinery which utilizes swing hammers to effect percussive rock breaking.

The object of the present invention is to provide a method and means for hard rock mining which will avoid the use of explosives and facilitate the transport of mined rocks. In this specification the word floor" is used and is to be understood to include the term footwall which is widely used in some mining fields.

According to this invention there is provided stope mining machinery comprising a movable assembly, means for moving the assembly, at least one driven rotor mounted in the assembly and carrying free swinging rock cutting hammers balanced to substantially avoid shock loading on the hammer pivots and with the axis of rotation of the rotor inclined to the plane of the stope floor when operatively positioned.

Further featuresof this invention provide for the inclination of the rotor axis to be such that it will, in use,

, lie at an angle exceeding 45 to the plane of the floor of a stope and when viewed in plan lie between 70 and 110 to the direction of traverse, for the machine to have two rotors, one mountedat a-higher elevation than the other and each having its axis inclined at an angle greater than 45 to the plane of the floor of the stope or for the machine to have three or more rotors.

To guide the material it is preferable to have, in most cases, chutes which may be open or boxed in and located at the discharge point of each rotor. Such chutes may be adapted to discharge onto a chain or belt conveyor or a stationary vibrating or shaking chute or onto the footwall at a specific distance from the stope face where it may be dealt with by some other device.

It is specifically envisaged that, where a conveyor is used, it will form a part of the guiding mechanism for the machinery during cutting operations.

Under certain circumstances it might be convenient to use ploughing devices instead of or in addition to the conveyor to move all or some of the broken rock to a suitable place for further handling.

The method of traversing the machine up and down a stope face may be by any of the recognized techniques. For example, a steel rope or ropes or a chain with a hoisting mechanism either incorporated in the machine or situated at a suitable point in or near the stope may be used. In steep mining the rope or the chain may be required in any event to prevent the machine from sliding down the stope under the force of gravity.

The machine itself will be mounted on wheels or on skids which would run directly on the footwall or on the conveyor structure mentioned above or on any other suitable guide. Some form of guide will in most cases be desirable to ensure that the machine is held at the correct distance from the face and to absorb forces which may develop during use of the machine and which tend to move the machine from its proper location adjacent the working face. 4

The guide mechanism and/or the conveyor, whether or not these are combined, is so designed that it can be moved forward towards the face and held in position by a number of extensible devices such as powered rams or simple mechanically extensible pushers anchored at the end furthest from the face by props or other suitable means.

Preferred embodiments of the invention are described below with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a sectional'elevation of the stoping machinery in a stope;

FIG. 2 is a plan of FIG. 1;

FIG. 3 shows a variation of the-rotor and conveyor arrangement; and

. FIG. 4 is a general plan of a stope with the machine partway down the stope face.

FIGS. 1 and 2 show the machine comprising a pair of rotors 1 and 2 each comprising two rows of four hammers together with their requisite/shock absorbers and generally as described in the US. Pat. No. 3,695,724 and US. application Ser. No. 230,246 now US. Pat. No. 3,778,113. Rotor 1 is set at an angle so as to cut slightly less than the lowerhalf of the height of the stope. In this arrangement the operation is so arranged that the actual gold bearing reef 3 is contained within the bottom half of the stope width. By stope width is meant the distance between the floor 4 wall 5 of the stope.

The rotor is driven from a suitable motor 6 which is conveniently an electric motor similar to those used in known types of coal cutters. Other motors may be used. The motor is coupled through a reduction mechanism 7 and a mechanical drive 8 to the rotor 1.

The reduction mechanism 7 can conveniently be a vee-belt drive and mechanical drive 8 can be a worm with the worm wheel mounted on the rotor shaft 9.

The mechanical drive is extended at 10 to connect the other rotor 2 to the motor 6 through a similar mechanical transmission. The rotor 2 is mounted such that it can cut slightly less than the upper half of the stope width. In order that this stope width be made wide enough to accommodate the machine, it is necessary that the axes of the rotors 1 or 2 be inclined to the floor of the stope. It will be apparent that the direction of inclination of the axes of the two rotors l, 2 are upward and downward respectively towards the working face.

In the embodiment illustrated inFIGS. I and 2 the motor 6, transmission 7, 8 and 10, and rotors l and 2 forming the basic machinery are rigidly held in fixed spaced relationship. Provision may be made-for adjustat each end. To stabilize the movement of the machine and hanging.

guide rails 13 accommodate formations 14 formed integral with the underside of the basic machinery. These guide rails ensure that the rotors l and 2 are positively located relative to the working face and will absorb forces which may develop during use of the machine.

Such use will cause rock to be broken by the rotors and when rotor 1 is in operation the broken rock includes the reef being mined and to be collected and transported for further treatment. This collection and transport is preferably effected by means of a belt or chain conveyor 15 and the guide rails 13 may be an integral part of the conveyor system. The belt will be positioned and adapted to receive rock broken by rotor 1 and transport this rock to a chute or other disposal means at the end of the working face. A spill plate 16 will be provided to contain the rock cut by the rotor draulic props 19. This arrangement also anchors the guide, rail 13 when the machine is in use.

When rotor 2 is in use it is adapted to throw broken rock into a chute 20 extending across the conveyor structure and having its discharge end remote from the working face to enable this rock to be utilizing to support the hanging wall in the mined out area of the stope. The chute 20 may include a conveyor belt or vi brating mechanism 21 to facilitate movement of the I I broken rock.

One or more control panels 22 are located at convenient positions on the machine to ensure protection is afforded to a driver while one or the other or both rotors 1, 2 are working. The controls will generally comprise various switches, valves and gauges in suitable electrical and hydraulic circuits and there will preferably be also some form of indicators and an automatic traverse speed feedback. As illustrated the rotors 1 and 2 are adapted to cut separately and during traverse of the face in opposite directions. Thus the control panel adjacent rotor 1 will be used where rotor 2 is working and vice versa. A canopy may also be provided to protect the operator.

To adequately support the basic machinery, skids 23 and 24 are provided and at least part of these skids 24 may, in fact, be the formations 14 cooperating with guide rails 13.

Hydraulic rams may be mounted between the basic machinery and the skids so that cutting elevations of the rotors can be varied to follow undulations in the reef 3. v y

Where the dip of the reef is such that broken rock will fall naturally to a collection point, the moving part of the conveyor structure can be replaced by fixed metal plates 25 shown in FIG. 3.

Under certain circumstances, it may be preferable to mount the rotor 2 above the rotor 1. Under these com ditions the drive assembly will have to be designed differently from that above described. Thisjis also illustrated in FIG. 3.

The machine may be modified in various ways from that above described without departing from the scope of the invention.

For example, a crane 26 may be' included to enable maintenance assembly and disassembly, to be readily in opposite directions and can be used to give a rock breaking operation similar to either climb or undercut milling in metal working practice. Thus, it may be possibleto cut the rock while traversing the working face in either direction. I

It is anticipated that machinery having more than two rotors will only be used where the stopes to are wide.

The basic machinery may be supported otherwise than on skids and may be carried on endless tracks or on wheels. These supporting members may be driven to move the basic machinery along its working path.

Also it will be appreciated that the basic machinery can be fixed to the chains 12 or other suitable flexible members such as wire ropes and these members can be driven from each end of the working face to move the machinery. v

More than two rotors can be provided particularly for use in wide stopes, in which one or more may be ad justable vertically and/or made to cut in advance of the remaining rotors. Where one of the rotors is made adjustable and to cut in advance of the others,sensing and control units can be incorporated so that automatic control of the adjustment of this rotor can be effected during use.

It is anticipated that the machinery and its use will have advantages over conventional hard rock mining techniques including accurate control of stope widths, support of the hanging wall close to working face, continuous operation, decrease indust production and better control of dust produced and these and other advantages should result in a reduction of labor and costs in the mining operations.

What I claim as new and desire to secure by Letters Patent is:

l. Stope mining machinery comprising a movable as-' sembly, means for traversing the assembly across a stope face, a rotor mounted in the assembly and rotatable'about an axis inclined to the stope floor when the assembly is operatively positioned, rock cutting hammers pivoted to the rotor to swing freely between end stops on the rotorduring use of the assembly, means for driving the rotor at -a rate enabling the hammers to swing into radial, operative positions under the influence of centrifugal force. the hammers being balanced to avoid shock loading on the hammer pivots during use of the assembly.

2. Stope mining machinery as claimed'in claim 1 inwhich the inclination of the axis of rotation of the rotor be mined when viewed in a plane normal to the direction of traverse of the machine in use, is greater-than 45 to the stope floor.

3. Stope mining machinery as claimed in claim 2 in which the inclination of the axis of rotation of the rotor when viewed in a plane parallel to the stope floor is between 70 and 1 to the direction of traverse.

4. Stope mining machinery as claimed in claim 3 in which there are two rotors mounted to operate at different elevations.

5. Stope mining machinery as claimed in claim 4 in which one of the rotors is adjustable vertically.

6. Stope mining machinery as claimed in claim 5 in which a sensing unit is included to controlthe position of the adjustable rotor.

7. Stope mining machinery as claimed in claim 4 including a conveyor for the material cut by the rotors.

8. Stope mining machinery as claimed in claim 7 in which a separate conveyor is provided for each rotor.

9. Stope mining machinery as claimed in claim 7 in which the conveyor provides a guide for movement of the machine during use.

10. Stope mining machinery as claimed in claim 4 in which the assembly is self-propelled.

l1. Stope mining machinery as claimed in claim 4 in which the assembly is moved by flexible members powered at each end of the working face along which the.

machinery is operated.

12. Stope mining machinery as claimed in claim 4 in which the rotorsare arranged with their axes oppositely inclined to the plane of the stope floor and set apart on opposite sides of the driving means for the rotor.

13. Stope mining machinery as claimed in claim 12 in which the rotors are connected to be driven in the same direction. v

14. Stope mining machinery as claimed in claim 12 in which a chute is provided to receive material cut by one rotor and a conveyor to receive the material cut by the other rotor with the chute extending across the conveyor.

15. Stope mining machinery comprising amovable assembly, means for moving the assembly, two driven rotors mounted in the assembly at different elevations and carrying free swinging rock cutting hammers bal anced to substantially avoid shock loading on the hammer pivots and with the axis of rotation of the rotors inclined to theplane of the stope floor when operatively positioned, the inclination of the axis of rotation of one of the rotors when viewed in a plane normal to the direction of traverse of the machine in use, being greater than 45 to the stope floor, the inclination of the axis of rotation of the one rotor when viewed in a plane parallel to the stope floor being between and 1 10 to the direction of traverse, one of the rotors being adjustable vertically.

l6. Stope mining machinery as claimed in claim 15 in which a sensing unit is included to control the position of the adjustable rotor.

l7. Stope mining machinery comprising a movable assembly, means for moving the assembly, two driven rotors mounted in the assembly at different elevations and carrying free swinging rock cutting hammers balanced to substantially avoid shock loading on the hammer pivots and with the axis of rotation of the rotors inclined to the plane of the stope floor when operatively positioned, the inclination of the axis of rotation of one of the rotors when viewed in a plane normal to the direction of traverse of the machine in use being greater than 45 to the stope floor, the inclination of the axis of rotation of the one rotor when viewed in a plane parallel to the stope floor being between 70 and to the direction of traverse, the rotors being arranged with their axes oppositely inclined to the planeof the stope floor and set apart on opposite sides of a driving means for the rotors.

l8. Stope mining machinery as claimed in claim 17 in which the rotors are connected'to be driven in the same direction.

19. Stope mining machinery as claimed in claim 17 in which a chute is provided to receive material cut by one rotor and a conveyor to receive the material cut by the other rotor with the chute extending across the con- 

1. Stope mining machinery comprising a movable assembly, means for traversing the assembly across a stope face, a rotor mounted in the assembly and rotatable about an axis inclined to the stope floor when the assembly is operatively positioned, rock cutting hammers pivoted to the rotor to swing freely between end stops on the rotor during use of the assembly, means for driving the rotor at a rate enabling the hammers to swing into radial, operative positions under the influence of centrifugal force, the hammers being balanced to avoid shock loading on the hammer pivots during use of the assembly.
 2. Stope mining machinery as claimed in claim 1 in which the inclination of the axis of rotation of the rotor when viewed in a plane normal to the direction of traverse of the machine in use, is greater than 45* to the stope floor.
 3. Stope mining machinery as claimed in claim 2 in which the inclination of the axis of rotation of the rotor when viewed in a plane parallel to the stope floor is between 70* and 110* to the direction of traverse.
 4. Stope mining machinery as claimed in claim 3 in which there are two rotors mounted to operate at different elevations.
 5. Stope mining machinery as claimed in claim 4 in which one of the rotors is adjustable vertically.
 6. Stope mining machinery as claimed in claim 5 in which a sensing unit is included to control the position of the adjustable rotor.
 7. Stope mining machinery as claimed in claim 4 including a conveyor for the material cut by the rotors.
 8. Stope mining machinery as claimed in claim 7 in which a separate conveyor is provided for each rotor.
 9. Stope mining machinery as claimed in claim 7 in which the conveyor provides a guide for movement of the machine during use.
 10. Stope mining machinery as claimed in claim 4 in which the assembly is self-propelled.
 11. Stope mining machinery as claimed in claim 4 in which the assembly is moved by flexible members powered at each end of the working face along which the machinery is operated.
 12. Stope mining machinery as claimed in claim 4 in which the rotors are arranged with their axes oppositely inclined to the plane of the stope floor and set apart on opposite sides of the driving means for the rotor.
 13. Stope mining machinery as claimed in claim 12 in which the rotors are connected to be driven in the same direction.
 14. Stope mining machinery as claimed in claim 12 in which a chute is provided to receive material cut by one rotor and a conveyor to receive the material cut by the other rotor with the chute extending across the conveyor.
 15. Stope mining machinery comprising a movable assembly, means for moving the assembly, two driven rotors mounted in the assembly at different elevations and carrying free swinging rock cutting hammers balanced to substantially avoid shock loading on the hammer pivots and with the axis of rotation of the rotors inclined to the plane of the stope floor when operatively positioned, the inclination of the axis of rotation of one of the rotors when viewed in a plane normal to the direction of traverse of the machine in use being greater than 45* to the stope floor, the inclination of the axis of rotation of the one rotor when viewed in a plane parallel to the stope floor being between 70* and 110* to the direction of traverse, one of the rotors being adjustable vertically.
 16. Stope mining machinery as claimed in claim 15 in which a sensing unit is included to control the position of the adjustable rotor.
 17. Stope mining machinery comprising a movable assembly, means for moving the assembly, two driven rotors mounted in the assembly at different elevations and carrying free swinging rock cutting hammers balanced to substantially avoid shock loading on the hammer pivots and with the axis of rotation of the rotors inclined to the plane of the stope floor when operatively positioned, the inclination of the axis of rotation of one of the rotors when viewed in a plane normal to the direction of traverse of the machine in use being greater than 45* to the stope floor, the inclination of the axis of rotation of the one rotor when viewed in a plane parallel to the stope floor being between 70* and 110* to the direction of traverse, the rotors being arranged with their axes oppositely inclined to the plane of the stope floor and set apart on opposite sides of a driving means for the rotors.
 18. Stope mining machinery as claimed in claim 17 in which the rotors are connected to be driven in the same direction.
 19. Stope mining machinery as claimed in claim 17 in which a chute is provided to receive material cut by one rotor and a conveyor to receive the material cut by the other rotor with the chute extending across the conveyor. 